Isn't the track index pulse == the one pulse that is fed to the PLL
phase comparator? That pulse is used to synchronize the oscillator
that must run at 12 (or 16) times the frequency between 2 sector
pulses to generate the (missing) sector pulses ....
or am I mistaken here?
- Henk, PA8PDP.
> -----Original Message-----
> From: cctalk-bounces(a)classiccmp.org
> [mailto:cctalk-bounces@classiccmp.org]On Behalf Of Paul Koning
> Sent: dinsdag 13 juli 2004 15:59
> To: cctalk(a)classiccmp.org
> Subject: Re: FW: RK05 question
>
>
> >>>>> "Fred" == Fred N van Kempen <waltje(a)pdp11.nl> writes:
>
> Fred> On Tue, 13 Jul 2004, Paul Koning wrote:
> David> the "home" slit and synthesize the individual sectors. Never
> David> tried this with an RK05 [heck havent touched one of them in
> David> over 25 years!], but I have used this technique to synchronize
> David> otgher items.....
> >> I suppose that's possible. One way to do it would be to build a
> >> PLL that's locked to the start of track pulse, and derive a 12x or
> >> 16x sector clock from that. Or, analogously, you could use a PLL
> >> to derive a 16 sector clock from the 12 sector clock (multiple by
> >> 4/3rd, not hard with a PLL). That's probably a good solution...
>
> Fred> Hm, and then ignore the "real" sector pulses and feeding the
> Fred> drive electronics the output of the PLL? Smart, that should
> Fred> work, assuming one can format the packs given this "sector
> Fred> clock".
>
> Yes, that's what I had in mind -- hook the optical sensor to the PLL,
> feed the PLL output to where the sensor used to go. The one obvious
> tricky part is to generate the track index pulse, because it isn't
> equally spaced along with the sector pulses.
>
> Fred> Would these then be called hard- or soft-sectored? :)
>
> Firm-sectored? :-)
>
> paul
>
I've tried twice to get VCF East Slashdotted with no success.
I'm not much of a writer and I carefully guard my Anonymous
Coward status on Slashdot. Maybe someone who is a better headline
writer and has some karma wants to give it a try?
>>>
>>> I guess there is more to an LLF (Low Level Format) than I realized.
>>> I had thought that a completely blank RK05 media was able to be
>>> FORMATed via an RK05 drive. Your answer seems to STRONGLY suggest
>>> that the media must first be SECTORed correctly.
>>>
>>> Otherwise, it should be possible to take and RK05 media and do an
>>> LLF on the drive using the system on which the media is to be used -
>>> and that it would not be a problem if the media originally had an
>>> incorrect number of sectors. Based on your answer, the RK05 media
>>> must FIRST have the correct number of sectors.
>>>
>>> Can you please confirm?
>>>
It would be VERY interesting if the drive had the capability to change the
number of mechanical "slits" in the hub on the pack.....
More seriously. I wonder how good the rotational stability is on the drive.
Mny of the reasons for using "hard sectored" media was because a) Drives
"wobbled", and b) Accurate timing electronics were "difficult".
If the drive motor speed is stable (over the course of a rotation),
it*MIGHT* be possible to alter a drive to just use the "home" slit and
synthesize the individual sectors. Never tried this with an RK05 [heck
havent touched one of them in over 25 years!], but I have used this
technique to synchronize otgher items.....
There is an excellent and growing "library" of old computer documentation
available at:
http://www.hartetechnologies.com/manuals/
The following additional specific manuals are being actively sought:
* AB Digital Design Labs B810 RAM
* CCS 2820 CPU Board Manual
* CCS 2-Serial/2-Parallel Card Manual
* Cromemco [2716] 32K Bytesaver
* Cromemco 64KZ and 64KZ-II Manuals
* DIGITEX Systems Manuals.
* DUAL Systems Manuals not listed.
* Ithaca Audio 1010 CPU Board
* Konan SMC200 SMD Disk Controller
* NNC ("No-Name Computers") Manuals
* OSM Computer Corp Z80 CPU "CPU/64K" Board
* S. D. Sales Expando-Ram I, II, III Manuals (any/all versions)
* SSM (Solid State Music) MB64 64K static RAM manual
* SSM VB3 Video board
* Zeus System Manuals
However, contributions of any manuals not currently in the archive are
appreciated (or "better" copies of documents that are already available).
If you have any of these in electronic format (PDF, JPEG, etc.), you may
contribute them by uploading them to:
ftp://ftp.hartetec.com/pub/incoming
Alternatively, if you have hard copy of any of these manuals, I hereby offer
to scan them to Adobe Acrobat PDF files and submit them, and, if requested,
return original manuals.
There are additional archives of old computer manuals at:
http://bitsavers.org/pdf/
and, for Processor technology products, at:
http://www.thebattles.net/sol20/sol.html
Barry Watzman
Watzman(a)neo.rr.com
Can RK05s that were used on a PDP-8 be used on
a PDP-11?
==
The drives are the same, the packs on PDP-8's are 16
sector instead of 12.
I'll trade you two tested/cleaned 12 sector packs for
every 16 sector one that you have.
>If anyone has any *crashed* 16-sector packs, it might be worth an >experiment to unclamp the hub and put it on a former 12-sector platter, >and reformat. I don't know if that's even possible, but it's an idea.
I'd be willing to donate a crashed 16 sector pack if someone wants to
try this. One has a very light scrach on an outer track. Don't know
if there is a way for these to mark bad tracks (would guess not).
Tim
_______________________________________________
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>From: "Marvin Johnston" <marvin(a)rain.org>
>
>
>
>"Dwight K. Elvey" wrote:
>>
>> Just out of curiosity, where does one find a 14V
>> Gell-Cell?
>
>Easy, just overcharge a 12V gel cell :).
>
Hi Marvin
I already have a few like this. Your welcome to the
ones in my yard. It'll save me a trip to the dump.
Dwight
Hi
Thanks.
Just out of curiosity, where does one find a 14V
Gell-Cell?
Dwight
>From: "Frank McConnell" <fmc(a)reanimators.org>
>
>Dwight Elvey wrote:
>> I just got a HP2113E. I've not been able to use it because
>> it wants to have a battery connected. There is suppose to
>> be a battery simulator plug for these. I'm looking for
>> any schematic or part information for this item?
>
><http://www.classiccmp.org/pipermail/cctalk/2002-December/012602.html>
>
>in which I wrote:
>
># Here I sit looking at a little black square 3x3 plug, HP p/n
># 12991-60002 (stamped in white ink on one side of the hood).
>
># Inside the hood (visible through the hole in the back) there is only a
># 1/4W resistor connected to pins 4 and 6, which matches Glen's
># description. Bands are gray, red, brown, gold. Hmm, 820 ohms?
># Measures as 823 ohms on my cheap digital multimeter.
>
>-Frank McConnell
>
Could you please transfer the images to files which can be
copied to bitsavers for download?
==
I should be able to do this, assuming the pack arrives in good
shape. Just went through some misery with some packs that Sellam
needed reading because the person who wanted them read didn't
know how to correctly pack and ship a 2315 cartridge (you don't
pack them 6 in a box with a little bubble wrap between them if
you expect them to spin when they get here).
Here's the deal...
I have two diablo alignment cartridges. I have 21 disk packs, 12 sector.
I am happy to give them all to the person who has the best chance to copy
the 21 packs to some media that I can read.
I am south of Boston, MA, USA.
I will also gladly give up the three diablo drives I have as well...
I have no controller (or else I'd do the reading myself) and no time (same
result).
Joe Heck
